Researchers are looking at many approaches to mitigate the effects of increasing carbon dioxide on the climate. A group of German scientists has proposed a technique that they call carbon farming, which may help remove carbon dioxide from the atmosphere.
The idea is to plant trees in arid regions on a very large scale in order to absorb carbon dioxide. Green plants are of course well-known to sequester atmospheric CO2. What is new about the German study is that it is the first time that experts in irrigation, desalination, carbon sequestration, economics and atmospheric sciences have combined to analyze the feasibility of a large-scale, comprehensive plan to capture carbon dioxide.
The research team proposes the use of Jatropha curcas, a small tree that is very resistant to aridity and that can grow in soils unsuitable for food production. Jatropha plantations would be sited near coastal areas where desalinated seawater could be used. One study showed that one hectare of Jatropha could capture up to 25 tons of CO2 each year. Plantations covering 3% of the Arabian Desert, for example, could absorb all the carbon dioxide produced by motor vehicles in Germany.
To be effective, the carbon in Jatropha would need to remain in long-term storage, or the plant would need to be converted to a biofuel that replaces fossil fuel.
Whether the economics would really work out and what other effects such large-scale plantations would have on the environment are not yet known. The German team hopes that there will be enough interest to establish a pilot project.
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Web Links
K. Becker, V. Wulfmeyer, T. Berger, J. Gebel, W. Münch. Carbon farming in hot, dry coastal areas: an option for climate change mitigation. Earth System Dynamics, 2013; 4 (2): 237 DOI: 10.5194/esd-4-237-2013
Photo, taken on August 17, 2013, courtesy of Nicholas Tonelli via Flickr.
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